1. Field of the Invention
The present invention relates generally to the fields of preventing infections. More particularly it provides novel broad spectrum antiseptic compositions that further have properties that allow them to be coated/impregnated into polymer surfaces or used as antiseptics in different applications. The invention provides methods for coating these antiseptic compositions onto medical devices such as catheters, tubes, stents and sutures, to prevent the growth of pathogens in such devices and hence, to prevent infection to patients via such devices. In addition, the invention provides novel antiseptics that could be used in disinfecting and sterilizing organic and inorganic surfaces, water and other fluids.
2. Description of Related Art
Most nosocomial infections are caused by the contamination of medical devices resulting in serious hospital-acquired infections. Nosocomial pneumonias are the second most common nosocomial infections, and are associated with the highest attributable mortality and morbidity. Recent data have shown that at least 300,000 episodes of nosocomial pneumonia occur annually in the United States (Official Statement, American Thoracic Society). The attributable mortality of this infection is 33%-50%, hence, around 100,000 patients die annually because of nosocomial pneumonia (CDC, 1993; Leu et al., 1989). The risk of nosocomial pneumonia increases 6- to 20-fold from the use of mechanical ventilation (Official Statement, American Thoracic Society).
The endotracheal tube is considered a common vehicle for colonization/contamination leading to nosocomial pneumonia. The endotracheal tube connects the oropharyngeal environment with the sterile bronchoalveolar space, significantly increasing the risk of nosocomial pneumonia. Endotracheal tubes are typically constructed of polyvinylchloride, which is known to be very difficult to impregnate with antiseptic or antimicrobial agents. Thus, there are no endotracheal tubes that are impregnated with antibiotics or antiseptics currently in use.
Another leading cause of serious nosocomial infections is bloodstream infections. The primary contributors to nosocomial bloodstream infections are vascular catheters. It is estimated that around 400,000 vascular catheter-related bloodstream infections (CRBSI) occur annually in the United States (Raad, 1998). The attributable mortality of these infections in the intensive care unit (ICU) was estimated in JAMA in 1994 to be 25% (Reiselman et al., 1994). Hence, these infections are a major cause of morbidity and mortality in hospitalized patients. These catheters are mostly polyurethane short-term catheters used in the ICU and long-term silicone catheters used in cancer/AIDS patients.
The most frequent causes of nosocomial infections are urinary tract infections (UTI), contributing to 34% of all nosocomial infections (Klempner et al., 1998). Nosocomial UTI are usually associated with contamination of urinary catheters. In addition, nosocomial surgical wound infections are common complications of surgical procedures, particularly in cancer and immunocompromised patients with devitalized tissue and decreased immunity. Surgical wound infections contribute to 17% of all nosocomial infections (Platt and Bucknall, 1988). Many surgical wound infections are associated with the contamination of sutures.
Antibiotics are strictly antibacterial agents that are usually used in treatment of systemic or bloodstream infections and are given through oral, intravenous, subcutaneous, or intramuscular routes to achieve systemic bloodstream levels. Examples include penicillin, cephalosporins, vancomycin, minocycline, and rifampin.
Antiseptics on the other hand, are antimicrobial agents often with broad spectrum antimicrobial activity against bacteria, fungi or viruses. These agents are used on the skin and external mucosal surfaces usually because of limitations related to absorption, penetration or systemic toxicity. These agents are not used in the treatment of bloodstream infections. Examples include chlorhexidine and povidone iodine.
Antibiotics and antiseptics have been used to impregnate vascular catheters. The concern with the use of antibiotics has been that resistance might develop to antibiotics, preventing their use therapeutically and systemically in hospitalized patients. Furthermore, the durability of the existing antiseptics has been limited. For example, the use of chlorhexidine/silver sulfadiazine on polyurethane surfaces has had limited effectiveness. Moreover, chlorhexidine/silver sulfadiazine impregnating the surface of vascular catheters resulted in limited activity against gram-negative bacilli, such as Pseudomonas. 
What is needed is an effective antiseptic having broad spectrum activity against resistant staphylococci, vancomycin-resistant enterococci, resistant Pseudomonas aeruginosa and Candida species, to be used in conjunction with indwelling devices that will inhibit or prevent the nosocomial infections typically associated with the use of these indwelling devices. It would be further desirable to develop devices impregnated with the antiseptic to enhance the resistance to infection. For example, the creation of antiseptic-impregnated catheters would prevent organisms from adhering or migrating on catheter surfaces.